Metal bellows are used in various technical fields as a component of variable length, for example, when it is necessary to equalize the length in lines or coupling connections for flowable media. In particular, metal bellows are also often used in hydraulic accumulators as a movable separating element between the gas side and the fluid side. Especially in applications where relatively extensive movements take place during expansion and compression of the bellows, or if back and forth movements take place at a relatively high rate and/or at higher acceleration values, as is the case in pulsation dampers or shock absorbers, it is important for the service life of the bellows that the respective end of the bellows moved along a housing wall in operation be guided in a safe and reliable manner.
In this respect, the prior art provides a guide on the movable end of the bellows involved. In a prior art solution published at a later date, disclosed in German patent application DE 10 2007 036 487.5, the guide arrangement is designed such that individual guide bodies distributed around the periphery of the end body are fastened to the peripheral edge of the movable end body of the bellows. These guide bodies form sliding bodies that are guided to mate with an outer sliding surface against the wall of the housing. The sliding surfaces of these bodies are spaced radially apart from the peripheral edge of the end body. Fluid passages are then formed along the housing wall between the individual guide bodies.
These guide bodies are designed as guide shoes. When the end body is configured in the form of a cup, the guide shoes overlap the peripheral edge of the cup having a circular cylindrical side wall extending into the interior of the bellows. When the guide bodies are made of a plastic material with good sliding properties, good guide properties are attained. When the friction ratio between the guide body and the housing wall is favorable, the guide provides safe and reliable long term operation. On the other hand, the production is complex and cost intensive. The individual guide bodies are fabricated in a separate production step and have to be brought to the assembly site and mounted on the end edge of the end body of the pertinent bellows. To ensure a reliable anchoring of the guide bodies, the guide bodies are designed as guide shoes, having a profile similar to the shape of a U in the cross section, with legs that overlap the end edge of the cup-like end body. In this context, the end edge of the cup has to have a catch, and the interior of the profile of the guide shoes has to have at least one undercut to secure the guide bodies with a snap lock action. The formation of the undercuts involves a time-consuming and costly production of the guide shoes by compression molding.